Composition of matter containing beryllia and alumina.



THOMAS B. ALLEN, OF NIAGARA FALLS, NEW YORK, ASSIGNOR TO THE CARBORUNDUMCOMPANY, OF NIAGARA FALLS, NEW YORK, A CORPORATION OF PENNSYLVANIA.

COMPOSITION OF IVIATTER CONTAINING BERYLLIA AND ALUMINA.

Leeann. No Drawing.

To all whom it may concern.-

Be it known that I, THOMAS B. ALLEN, of Niagara Falls, Niagara county,in the State of New York, have invented a new and useful Composition ofMatter Contalnlng Beryllia and Alumina, of which the following is afull, clear, and exact description.

My invention is designed toprovide a new and useful composition ofmatter containing oxids of aluminum and beryllium. The composition is ofa crystalline nature and forms abrasive grains which are Valuable forabrasive and other purposes.

In the manufacture of the new product, I preferably melt a mixturecontaining the oxids of aluminum and beryllium in an elec' tric furnace,such, for example, as shown in United States Patent No. 929,517, grantedto F. J.'Tone on July 27th, 1909. This furnace is of the arc type withvertical electrodes depending into its crucible; and the oxid mixturemay be gradually fed; into the furnace around the electrodes duringpassage of the electric current, until the furnace is filled with themelted mixture to any desirable amount. The current is then turned offand the material allowed to cool; when the ingot may be removed from thefurnace and crushed into grains of various sizes, such as are used forabrasive purposes.

Instead of using a mixture of the oxids of aluminum and beryllium, I mayuse any ore or ores or minerals as a source of either or both of thesematerials. Thus, as a source of alumina I may usean ore or mineral, suchas bauxite, which may contain in addition to alumina other materialssuch as oxids of iron, silicon, and titanium. As a source of beryllia,any natural ore may be employed containing this substance, and alsocontaining other materials such as oxids of aluminum, silicon, iron, &c.I prefer to use bauxite as a source of alumina, and the mineral known asberyl as a source of beryllia; though I do not wish to limit myself toany particular material containing such oxids.

The mixture of bauxite and beryl is pref erably made up with asufiicient amount of carbon or other reducing material, to remove themajor portion of the oxid of iron and of the oxid of silicon. It is alsopreferable to add to the mixture, oxid of iron or some other basicmetallic oxid, in order to more readily remove the reduced silicon andtitanium.

Specification of Letters Patent.

Application filed November 9, 1910. Seria1 No. 591,495.

Patented Aug. 22, 1911.

As an example of my preferred method, I have melted together a mixtureof100 parts calcined bauxite, 75 parts beryl, 50 parts oxid of iron, and12 parts of coke in an electric furnace, these proportions being byweight, and after melting and reduction have obtained a productcontaining 7% per cent. of beryllia and 89 per cent. of. alumi'na,.

the remainder consisting mainly of'the'oxid of iron, silicon andtitanium. The beryllia should be present, to less than eighteen percent, that is, less than that represented by the chemical formulaBeOAl,O,. If such per cent. of beryllia is exceeded, an excess ispresent which would either crystallize out as beryllia or form berylliumaluminate of less hardness. In this reducing operation there ispractically no reduction of oxid of aluminum or oxid of beryllium, sincethe heat of formation of these oxids is higher than that of the otheroxids present.

- The amount of silica and other oxids re maining in the product willdepend upon the amount of oxid of iron and of carbonaceous materialadded. The alloy consisting of iron, silicon and titanium formed byreducing the impurities in the melted mixture may be separated from thedesired product either during or after the furnace operation.Mechanical, electrical, or chemical means may be used for thisseparation after the fused mass is removed from the furnace.

The abrasive qualities of the product vary with the content of berylliaand other oxids; and by varying the composition andxproportions I canprepare a number of pr nets of difiering degrees of hardness andtoughness. The content of beryllia gives to the product an improvedcrystallization; while the toughness of the product decreases as theamount of beryllia is increased. The hardness of the product, however,mcreasesas the amount of contained beryllia is increased.

The mixture of the charge may be varied, any desirable form of furnacemay be employed, and many other changes may be made Without departingfrom my invention.

I claim 1. As a new composition of matter, a homogeneous crystallineproduct containing alumina and also containing beryllia to not exceedeighteen per cent.

2. As a new article of manufacture, a homogeneous crystalline productconsisting of alumina, and beryllia substantially free from impurities,and containing not to ex- .ceed'eighteen per cent. beryllia.

3. As a new article ofmanufacture, a homogeneous crystalline productconsisting of alumina and beryllia, the proportion of beryllia beingless than that represented by the chemical formula BeOAl O 4. Theprocess of forming the herein described product which consists ofmelting by electrically developed heat a mixture containing alumina,beryllia and carbon, substantially reducing the impurities,'allowing thefluid mass to cool, and separating the crystalline product from theimpurities.

,5. The process of forming the herein-described product, Which consistsof melting by electrically developed heat a mixture containing alumina,beryllia, and a reducing agent, substantially reducing the impurities,allowing the fluid mass to cool, and separating the crystalline productfrom the impurities.

In testimony whereof, I have hereunto set my hand.

L. B. COULTER, C. S. GREENWOOD.

